A white light-emitting device is configured by combining, for example, a luminescent material which emits red light by excitation with blue light, a luminescent material which emits green light by excitation with blue light, and a blue LED. When a luminescent material which emits yellow light by excitation with blue light is used, the white light-emitting device can be configured by using fewer kinds of luminescent materials. As such a yellow-emitting luminescent material, for example, an Eu-activated orthosilicate luminescent material is known.
There is an increasing need for the yellow-emitting luminescent material to improve temperature property, quantum efficiency, and luminescence emission spectrum half width.